This invention relates generally to flooring tools, and in particular to powered groovers for use with flooring materials and the collection of chips and dust created by their use.
In the installation of certain sheet vinyl flooring materials, such as Armstrong Medintech solid vinyl or Forbo Marmoleum linoleum, seams in the sheets of the material may be grooved and welded. These types of flooring materials are preferred for hospitals and kitchens because the seams can be completely fused together with the welding process. The welding of seams prevents pathogens from growing in the seams. Powered groovers are also used with other types of flooring materials not made from vinyl, such as commercial linoleum.
These sheet flooring materials come in rolls of a fixed width. The installer cuts multiple sheet lengths to the desired dimensions for the room, and then adheres them to the floor using adhesives. At the seams, the installers often use an electrically powered vinyl groover to form a precision groove in the seam, which can later be filled by heat welding filler material into the groove. Prior art electrically powered vinyl groovers are typically specialized adaptations of electrically powered circular saws or routers. Typically the saw motor has been pivotably mounted on a base having guide wheels. The guide wheels track in the seamline, thereby ensuring that the blade is always centered on the seamline as the groover is wheeled down the seam. The spring-loaded pivot enables the blade to be moved angularly up or down. Thus, the spinning blade may be plunged into the seam at the start of the grooving operation, and is automatically raised out of the groove at the end.
Excessive cuttings and dust from power tools are undesirable especially in hospital and kitchen installations. Hence, most prior art power groovers have some capability to collect cuttings within a removable bag for disposal. The collection system for most prior art groovers has functioned as follows: As the blade moves through the material, cuttings accumulate on the teeth and are subsequently ejected from the blade within a blade housing. The cuttings fly off the teeth on a tangent. Airflow generated by the spinning circular saw blade is used to carry the cuttings to a strategically positioned hole in the blade housing, then through a duct leading to an attached collection bag. The user can easily remove the bag and dump the cuttings. However, with increasing labor costs for cleanup, and increasing liability concerns in hospital construction, flooring installers prefer an improved dust and cuttings collection system. One way to improve upon this type dust and cuttings collection system would be to provide means of increasing the amount of airflow directed towards the duct.
In prior art power groovers, the blade housing is defined physically in terms of a first inner wall, a second outer wall, a third perimeter wall joining the inner wall and outer wall, and a fourth bottom wall. The inner and outer walls have in some cases been integral surfaces of cast parts having fairly sheer inner surfaces. In other groovers, the outer wall is formed by means of a separate cover plate, but the inner surfaces of such cover plates have also been sheer. The third perimeter wall extends perpendicularly to connect the inner and outer walls. With respect to groovers having cover plates, the cover plate is typically fastened to the perimeter wall.
The blade housing castings for some groovers have an integral bottom wall. Others have a separate catch component that is typically mounted to the base. Either design includes a slot through which the blade may pass.
For example, in a prior art groover called the Frasjunior, manufactured by Wolff Tools of Germany, the blade housing is an integral cavity in an adapter casting which is fastenable to a router type motor. The blade housing cavity appears to have been formed by a “lost wax” or “breakout mold” type insert placed inserted within the die. This shape of the insert creates a blade housing with a sheer vertical inner wall, a sheer vertical outer wall, and a perimeter wall. The bottom wall is formed by a separate catch component fastened to the base.
The casting forming the blade housing includes a forward pivot arm. The motor and blade housing are mounted to the base at the pivot arm. The blade passes through the catch on the base to cut the groove.
Forming raised features such as bosses or ribs within insert cavities such as this groover's blade housing can be quite complicated, as the insert becomes very difficult to remove. In fact, the blade housing of the Frasjunior in fact has no such raised internal features. Hence, neither the inner wall, perimeter wall, or outer wall of this blade housing have any raised features such as bosses or ribs formed on or fastened to them which may serve to increase the forcefulness of airflow towards the inlet hole of a their duct.
In another prior art groover called the Grooving Machine EASY 5000, manufactured by Roll Bodentechnik, Ltd. of Germany, the blade housing is formed by a casting fastened on one side to the motor. On the opposite side, the casting forms an integral inner wall and perimeter wall for a blade housing. A separate cover plate fastens onto holes tapped in the perimeter wall to form the blade housing's outer wall. The separate cover plate simplifies the casting process as no inserts are required. The bottom wall is formed by a separate catch fastened to the base. Neither the inner wall, perimeter wall, or inner surface of the cover plate forming the outer wall of this blade housing have any raised features such as bosses or ribs formed on or fastened to them which may serve to increase the forcefulness of airflow towards the inlet hole of their duct. However, the inner wall of this groover's blade housing does contain a hollowed slot that will be discussed below in relation to its inlet hole.
In another prior art groover called the Frasmaster (also manufactured by Wolff Tools of Germany), the blade housing is formed by a first, inner wall made from a flat metal plate mounted at a right angle to the base. A cast cover defining the outer wall and the perimeter wall is fastened to the plate to form the outer wall of blade housing. For its bottom wall, this groover includes a separate catch mounted to the metal plate. In this design, the blade housing is fixed, and motor spindle and attached blade are designed to move up and down within the blade housing, by means of a pivoting mount located outside the blade housing. Hence, the plate includes a slot through which the motor spindle passes into the blade housing.
With respect to the Frasmaster groover, the motor mount and pivot arm are separate components from the blade housing, making this tool more complicated and expensive. Furthermore, the inner wall, outer wall, and perimeter wall of the blade housing of the Frasmaster have no raised features such as bosses or ribs formed on or fastened to them which may serve to increase the forcefulness of airflow towards the inlet hole of a duct.
In another prior art groover, the Leister BA Flooring Groover manufactured by Leister Process Technologies of Switzerland, the blade housing is one integral shape in a large, multifaceted casting also forming the base for the tool. Hence, the blade housing is fixed to the base, and (similarly to the Frasmaster) the blade moves up and down within the blade housing. The inner wall and perimeter wall of the housing are formed in the base. The outer wall is formed as a cover plate fastened to the perimeter wall. The blade housing of this groover has an integral bottom wall with a slot for the blade. The hinged motor mount for this groover is mounted to the base outside the blade housing Oust as the Frasmaster). Hence the inner wall requires a large hole through which the motor spindle may pass.
With respect to the Leister BA Flooring Groover, having the base casting include an integral blade housing requires a large, complicated die with high up-front tooling investment. It is also noted that the inner wall, outer wall, and perimeter wall of the blade housing of this groover also have no raised internal features such as bosses, ribs, or protruding components formed on or fastened to them which may serve to increase the forcefulness of airflow towards the inlet hole of a duct.
Each of the blade housings for these prior art groovers also includes an internal inlet hole for an integral duct having an outlet outside the blade housing. The hole and the duct are positioned to convey cuttings from the blade using the force of airflow to an outside collection bag. Airflow is generated by the spinning circular groover blade. Cuttings fly off the teeth on a tangent. For these reasons, it is preferred that the internal hole be positioned at some point trailing the spinning teeth of the blade Furthermore, it is preferred that this hole be centered longitudinally on the vertical plane defined by the blade, as airflow down the hole will be most forceful on this center. Lastly, it is preferred that the perimeter wall of the housing extend vertically to a point substantially tangent to the upper edge of the inlet hole and upper wall forming the top of the duct. This way the airflow does not change direction on its way down the duct and thereby lose forcefulness.
In prior art groovers, the inlet hole has typically been located in one of two areas within the blade housing. For the Leister BA Flooring Groover, the hole is located at a forward location nearest the area where the teeth of the blade first enter the blade housing. This location is preferred because it is near the area where cuttings first come off the teeth and have high velocity. However, for greatest effect, this type of duct must be oriented vertically. The Leister BA Flooring Groover also includes a secondary tube attached at the outlet of the duct having a bend at its distal end. The tube raises the collection bag above the groover, keeping it out of the way of the motor. The bent end directs the bag away from the user or wall surfaces.
The ducting of the Leister groover requires a number of costly components which are unnecessary and reduce the usability of the tool. Ejecting the cuttings vertically means that the cuttings are slowed by gravity and can tend to fall back into the blade housing. Hence the Leister groover includes a fan within the blade housing to generate additional airflow. This makes the blade housing of this tool very large, creating a heavy and bulky tool. Furthermore, the vertical tube places the collection bag in the users' line of sight along the seamline.
The Frasmaster groover has a similar, forward hole within the blade housing, and also includes a secondary, vertically oriented tube mounted on its vertical duct. However, this groover does not have an internal fan within the blade housing as the Leister does.
The Frasjunior groover has a hole located at a rearward location within the blade housing. The airflow from the blade is powerful enough to carry most cuttings through the rearward hole and down the rearward projecting duct. The collection bag can be mounted directly on the duct as it faces behind the motor and the user. This design is preferred for better usability and economy of components. However, not all cuttings enter a reward hole due to inadequate airflow. If more airflow generated by the spinning blade could be focused towards the rearward hole, cuttings collection could be improved, without the need for a bulky or significantly more expensive tool.
The Grooving Machine EASY 5000 has a rearward located hole and rearward duct, similar to the Frasjunior. The inner wall of the Grooving Machine EASY 5000 includes a slot hollowing an area in front of and beneath the inlet hole. Presumably, in the process of die making, the inner wall was inadvertently made too thick, with the result that it blocked half of the hole. As a result, the inner wall had to be hollowed to expose the hole. The relieved slot creates an eddy at its leading edge. Furthermore, airflow must divert into the slot to enter the inlet hole, reducing its force. It would be preferable to have an inner wall that did not block such a large portion of the inlet hole, and other additional features that actually tended to divert additional airflow towards the inlet hole.